Psp 2001 not reading umd discs

This is a followup to a recent forum board post that I did. I have a psp 2001 series that isn't reading umd discs. The disk drive broke before covid started and I didn't know about ifixit.com. My psp has a umd disk drive KHM-420 BAA.

I changed the disk drive and my psp still isn't reading umd discs. What happens is that the system attempts to read the disc, the little animation symbol appears in the lower right hand corner, but the title of the disk never appears on screen. I have some ideas.

1) There is something else that I need to do after changing the umd disk drive

2) I got a bad part off of amazon

3) There is another hardware part besides the umd drive that reads umd disks.

4) I have an unsolvable problem.

I have replaced disk drives before. My psp isn't jailbroken in any way. I can do other things like see game saves, use the psp wifi. I can't imagine what the problem might be.